The word often has more than two types of pronunciation:
often [‘ɔf(ə)n] / [‘ɔft(ə)n]
часто, много раз
Let us see how Princess Elizabeth says it. We have two sentences with this word:
Our father and mother have so often talked to us of their visits to different parts of the world. Папа и мама часто рассказывают нам о своих поездках в разные уголки мира.
I am sure that you, too, are often thinking of the Old Country.
Я уверена, что и вы, тоже, нередко вспоминаете свою Родину.
As you may have noticed, there is a slight difference in the pronunciation of often in these utterances. In the first one often has a very weak [t], it is hardly there at all, although it is there, one may say as a trace of the sound [t].
And in the second instance [t] is quite audible.
Since both variants of pronunciation are used in King’s English, we may be free to choose which one suits us best. Or, on the other hand, why not use both, interchangeably?!